The <NameIDMgmt> element is used to enable and configure support for Name Identifier Management protocols within the SP. It is rarely used. It element automates the installation of the appropriate handlers based on the protocols selected for activation.
The content of the element is a whitespace-delimited list of "protocol" identifiers. The following are built-in to the SP:
SAML 2.0 Name Identifier Management profile (front- and back-channel, IdP-initiated only).